1. Field of the Invention
The present invention relates to burs for grinding denture teeth. More specifically, the present invention relates to a pair of burs that can be used in conjunction to grind denture teeth so that the teeth have a lingual occlusion.
2. Description of the Related Art
For many years dental professionals have sought to produce dentures that would be esthetically pleasing, while still being comfortable and functional for the wearer. Many of the problems associated with dentures arise from the fact that the top denture plate is a unitary piece and the bottom denture plate is also a unitary piece and neither plate attaches securely in the wearer's mouth. Thus the top plate and the bottom plate each functions as a unitary tooth that can tip or rise up within the wearer's mouth.
For this reason, it is important that the teeth be positioned relative to each other to maximize chewing efficiency and to minimize tipping and raising up of the dentures. One of the more popular ways of making dentures is to make them with lingual occlusions. A lingual occlusion is where the maxillary lingual cusp is the dominant functional element, and occludes against the corresponding portion of the mandibular tooth. The mandibular teeth of a lingual occlusion are of two general types: they are either flat or they have a slight angulation. It is the latter group of dentures that the present invention is used to create, i.e. dentures with lingual occlusions that employ mandibular teeth with slight angulation and an area usually in the center of the lower tooth that will occlude with the upper tooth lingual cusp.
The angulation of the mandibular teeth in this type of lingual occlusion is slight so that the teeth can grind together to chew food without causing the plate to tip or be kicked up. The mandibular teeth must be shaped so that the fossae of the mandibular teeth are not too deep, the fossae properly receive the maxillary lingual cusps, and the angulation of the mandibular teeth is properly sloped. Currently, there are no burrs to allow a practitioner to quickly and accurately shape the mandibular teeth into the ideal sloped configuration.
The present invention addresses this problem by providing a pair of burs that can be used to shape the mandibular teeth into the proper sloped configuration required for lingual occlusion of the dentures. Specifically, the present invention is a pair of burs that include a first bur for cutting the cusps of the mandibular teeth while not cutting the fossa and a second bur for cutting the fossa of the mandibular teeth while not cutting the cusps. The first bur is provided with a non-cutting central port-on that is flanked by two slightly angled cutting surfaces, and the second bur is provided with a cutting central portion that is flanked by two slightly angled non-cutting surfaces. The burs are used sequentially; i.e. the first bur is used followed by use of the second bur, to achieve the desired slope and center fossa for the mandibular teeth for dentures.
The angulation of the two cutting surfaces on the first bur may or may not match each other on a given set of burs, and the angulation of the two non-cutting surfaces on the second bur may, or may not match each other on a given set of burs. However, the angulation of the slightly angled cutting surfaces provided on the first bur and the angulation of the slightly angled non-cutting surfaces provided on the second bur match each other for any given set of burs. It is important that the first and second burs in a set of burs match so that the non-cutting surfaces of the second bur will fit with the tooth after the tooth has been shaped with the cutting surfaces of the first bur and so that the non-cutting central portion of the first bur will fit with the tooth after the tooth has been shaped with the cutting central portion of the second bur, thus preventing the possibility of cutting away too much of the tooth.